Impurity

From Tadanohito:

This guy in a coma in the hospital finds that he can leave his own body, and enter other men. He then realizes that he can sense what they sense, so this leads to sex with nurses and patients, all as different men. Of course each person he occupies has their own back story, so he often gets more than he bargained for. This story is full of supernatural stuff, and ends with something similar to tentacles. Not a light read. Light censorship.